Trimming mechanism for sewing-machines



(No Model.)

J. D. ALLEN & H. B. WALMSLEY.

TR'IMMING MECHANISM FOR SEWING MACHINES. N0x 248,977. PatentedNov. 1,1881.

Inventors. @{f iTrwwca ,(j; m

STATES PATENT OFFICE JOHN D. ALLEN AND HARRY B. WALMSLEY, OF LYNN, MASSACHUSETTS.

TRlMlVllNG MECHANISM FOR SEWING-MACHINES.

SPECIFICATION formingpart of Letters Patent No. 248,977, dated November 1, %881,

Application filed December 13, 1880.

To all whom it may concern Be it known that we, JOHN D. ALLEN and HARRY B. WALMSLEY, both of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Trimming Mechanisms for Sewing- Machines, of which the following is a full, clear, and exact description.

This invention relates to an improved mechanism to be combined with and arranged upon any of the ordinary sewing-machines, and to be operated in conjunction therewith for trimming or cutting from time to time the material being sewed, and in a line parallel with the line of seam or stitch, and it is especially useful and applicable in leather sewing for boots and shoes and other articles of leather manufacture. I

This improved mechanism in itself and in its connection with sewingmeehanism consists, in substance, of a bar which carries a cutting blade or knife suitable to cut and trim, as desired, the material being sewed, and which 'is located and arranged at one side of the needle-bar to move and be guided vertically and in a parallel line therewith, and to have its knife-edge at or near, but preferably at and in advance of, the sewing-needle, in combination with two springs, which are arranged upon or in relation to said knife-bar (the one above the other) for each to be downwardly compressed in a downward movement of the needle-bar, and to be relieved of such compression in an upward movement of the needle-bar and otherwise, all in such manner that through the downward compression of the one spring the cutter-bar is moved downwardly, carrying with it its knife-blade into and through the thickness of the material being sewed, and the other spring is compressed downwardly, and that through the upward release of the downward pressure upon the spring, the downward compression of which moved the cutter-bar downwardly, the other spring is released to react in an upward direction upon the cutter-bar, and thus to raise the cutter-bar to its normal position, to be again acted upon, as above, in the neat downward movement of the needlebar.

In the accompanying plate of drawings the present invention is illustrated in connection (No model.)

c is a bar having fixed to one end of it a knife or cutting blade, (I. This bar 0 is at one side of the needle-bar, and is there arranged to move and be guided and play vertically and in a parallel line with the needlebar, and to have the cuttingedgefofits blade presented downwardly to the throat-plate back of the needle and in a line commencing at or near the needle and extending in advance thereof, or, in other words, in the same direction as that of the travel of the material being sewed by the feed of the machine.

g h are two spiral springs surrounding the knife-bar c, and arranged the one above and separately from the other. The upper spring, g, at its lower end rests upon a fixed collar, l, (but-adjustable vertically by set-screws m,) of the knife-bar c, and the lower spring, h, at its lower end rests upon a stationary bearing, a, of the head-stock A of the machine, through which both the needle and knife bars I) 0 move. Above the upper end of the upper spring, g, the knife-bar c is surrounded loosely by a horizontal arm, 0, fixed to the needle-bar, but adjustable "ertically by set-screw p, and above the upper end of the lower spring, h, the knife bar is provided with a collar, 1*, fixed to it, but adjustable vertically by set-screw s.

The upper spring, g, and its under supporting-collar, l, of the knife-bar, together with the horizontal arm lapping from the needle-bar over the upper end of such spring, are adjustable in such relation to each other that in the downward movement of the needle-bar its needle will have first entered into the material being sewed before the said horizontal arm 0 will abut against the upper end of the upper spring, g, and that in the then continued downward movement of the needle-bar to the completion of its stroke in that direction the said bar through the downward movement of the needle-bar, as above described, will downwardly compress such spring it against its stationary support without at the same time, to any material or practical extent, inteifering with the downward movement of the knifebar by the compression of its upper spring, as aforesaid. The needle-bar, having completed its downward stroke, then moves upward, and as movement of the needle-bar. In this manner it is plain that the cutting'edge ofthe knife is made from time to time to out into and through the material being sewed, and obviously, it its cutting-edge be properly situated relative to the needle, and the material be properlyguided through the machine, a trimming of the material being sewed will and can be had in aline parallel with the line of sewing or seam.

The knife-bar 0 may be round or square sided, and in either case the guideways n t for it are to be correspondingly shaped, and obviously when square-sided no rotary movement of it can occur as it travels up and down; but when round, while such might be the case, yet it is easily prevented, and in many obvious waysas, for instance, such as shown in the drawings, which consists in providing its upper-collar, l, with a vertical pin, u, to play into and through a hole, t), in the head-stock ot' the machine.

The trimming mechanism herein described obviously may be operated directly from the arm which throws the needle-bar, instead of from theneedle-bar, as has been described, and again directly frotn the driving parts of the machine, instead of through either the needlebar or the lever-arm operating it, the essential partin this regard being to simply secure down ward pressure upon the knife-bar under a principle of operation substantially such as has been described. Again, the downward pressure desired upon the knife-bar may be put upon it as well through the lower spring as the upper spring, provided, of course, the relative arrangement of the spring be reversed. The point of the knifeblade is of such length that it is never lifted above and out from the guiding-slot in the usual throat near the needlehole.

Having thus described our invention, what we claim, and desire to secure by Letters Patent, is-

1. In a sewing-machine, a knife-carrying bar adapted to be moved vertically in guideways, in combination with two springs, one of which is arranged in relation to said bar and to the operating mechanism of the machine to secure a downward movement of the knife-bar under a compression of the spring, and the other an upward movement thereof on a release of such compression, whereby the knife-bar is raised to and held in its normal position, ready for operation again, substantially as and for the purpose described.

2. In a sewing-machine, a knit'e-carryingbar adapted to be moved vertically in guideways. and having collars or shoulders l r and springs g h, in combination with an arm, 0, raised and lowered by the operating mechanism of the machine, to secure the lowering and raising of knife-bar c, all substantially as and for the purpose described.

3. In a sewing-machine, aknife-carrying bar adapted to be moved vertically in guideways, and having collars or shoulders 11' and springs g h, in combination with the arm 0 of the needle-bar b, all severally arranged for a co-operative action in the downward-and-upward movement of the needle-bar, substantially as and for the purpose described.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

JOHN D. ALLEN. HARRY B. WALMSLEY.

\Vitnesses:

OYRUs O. MAYBERRY, GEORGE W. DAVIS.

I I t 

